For one night, and most of one day if you happened upon the parking lots, Parrothead Nation took over the Xfinity Center in Mansfield, as Jimmy Buffett's annual beach party of Caribbean-themed rockin' 'n' reeling provided a sellout throng of 20,000 with the soundtrack for a hedonistic frolic/communal catharsis.

Buffett and his Coral Reefer Band performed roughly 27 songs over their 2 hours 15 minutes on stage, and if that tally is approximate, it's only because of several artful medleys which combined songs. Since guitarist Peter Mayer's son Brendan is fresh out of Boston University--with a history degree, like Buffett, as the singer gleefully noted--he joined the Coral Reefers for about a third of the night, including debuting his own tune, "Something to Say.". That swelled the Coral Reefers' ranks to twelve, and the musical arrangements, anchored by longtime keyboardist Michael Utley, Peter Mayer, and Mac McAnally on guitars, were superb all night, as was the sound mix. If anything, after not hearing a Buffett show for a few years, we were surprised at how hard many tunes rocked--the rendition of the Grateful Dead classic "Scarlet Begonias" was as torrid and visceral as that tune has ever sounded.

But if the overall production is first class and a well-oiled machine, the fulcrum is still the man himself, barefoot in blue shorts and a purple tee shirt, but with his baritone in fine form and clearly enjoying his return to Mansfield. Buffett's relaxed song introductions and vignettes about past concerts at the former Great Woods gave the whole night the atmosphere of a family reunion. At this point, the convening of Parrothead Nation is much like a traveling circus, and Buffett is an affable ringmaster, still amused at his fans' antics and grateful for their support.

It's become a tradition in recent years for Buffett's video screens to show fans from the parking lot pre-show revelry, and last night's choices were typically wacky, from the man with the shirt reading "they said I could only have one!" as he stood by a washtub-sized cocktail glass, to the lady in the bikini who helpfully flashed the camera. We actually walked in behind a fellow wearing a shark-fin hat, a grass skirt, and nothing else, save the arm tattoo that told you he was 'Dom.'

Buffett, 67,† has become one of the music world's most beloved concert acts in part because he knows what the fans want to hear; hence the core group of eight songs you're almost certain to hear at every show, like "Cheeseburger in Paradise," "Come Monday," "Son of a Son of A Sailor" and so on. But Saturday's show also included some tasty covers, from a rollicking take on James Taylor's "Mexico," to Zac Brown's "Free" with its diversion into Van Morrison's "Into the Mystic."† By this time of course, Stephen Stills' "Southern Cross" is such a Buffett concert staple, with such a perfectly apt sailing storyline, it almost seems more like a Buffett tune.

Buffett has also become a popular guy for today's generation of country stars, and a few have seemed to adopt (or hijack) his Caribbean beach party persona (we're looking at you, Kenny Chesney). But those songs and duets have allowed Buffett to attract a whole generation of fans--we were surprised at the percentage of college age fans Saturday night--and now 2007's collaboration with Alan Jackson, "It's Five O'Clock Somewhere" has earned a slot in the core repertoire--and was last night's first encore.

But the most salient thing about Buffett is just that he is such a brilliant lyricist, whose early work was much more country-folk, before the whole beach party thing took off. Back in those days, when he was playing the old Paul's Mall on Boylston Street, it was both the poignance of a tune like "Come Monday," and the wit behind country-tearjerker-parodies like "My Head Hurts, My Feet Stink, And I Don't Love Jesus" that set Buffett apart. Even his biggest hit, and musical signature, "Margaritaville," is, at root, a classic lost-love country ballad, with an appealing dose of self-deprecating humor, and the kind of steel-drums flavor that gives it a life-affirming air.

Buffett has a real affinity for this area, ("thanks Don Law" he said at one point), and whether he was adding a "Dirty Water" snippet to "We Are the People Our Parents Warned Us About" or dedicating "A Pirate Looks at Forty" to a late Nantucket buddy, Johnny Krebs, his affection was palpable.

Favorite moment: during a raucous "Fins," Buffett was so busy making shark motions with his arms at fans at stage right, he realized suddenly he was too far away to get back to his mike for the next verse. Mac McAnally jumped in and sang the line as a laughing Buffett rushed over too late. It was that kind of night, great songs, a terrific big band, warm feelings abounding, and plenty of goofy fun.